JP6130408B2 - Element forming method and apparatus for continuously variable transmission belt - Google Patents

Description

  The present invention relates to a method and apparatus for forming an element of a belt for a continuously variable transmission.

  In general, an element of a continuously variable transmission (CVT) belt includes a body provided on both sides with V surfaces contacting a pulley of the continuously variable transmission, and a head connected to the body via a pair of grooves. . An endless ring is attached to each of the pair of recesses, whereby a plurality of elements are bundled in an annularly stacked state.

  A recess is formed near the center of the front surface of the head. And the convex part is formed in the center part vicinity of the back surface of a head corresponding to the dent of a recessed part. When the continuously variable transmission belt is formed, the convex portions of the elements stacked adjacent to each other enter the concave portion, whereby the mutual positional relationship between the elements is determined.

  The element is formed by punching a metal plate material using a die, a punch or the like. Conventionally, as a method for forming an element, there is a method including a punching process for performing punching processing while leaving a connection portion with a plate material in a part of the element, and a separation step for completely separating the connection portion from the plate material by cutting the connection portion. It is known (see, for example, Patent Document 1). In this forming method, the concave portion and the convex portion are formed by shearing simultaneously with the punching of the element in the punching step.

JP 2001-232424 A

  However, in the conventional technique described in Patent Document 1 or the like, when the concave portion and the convex portion are formed by the shearing process simultaneously with the punching of the element in the punching process, the material generated by the shearing process flows, There was a case where the convex portion was contracted.

  In view of the above, an object of the present invention is to provide an element forming method and an apparatus for a continuously variable transmission belt, which can reduce the possibility that the concave portion or the convex portion of the element is damaged.

  An element forming method for a belt for a continuously variable transmission according to the present invention includes a body having V surfaces on both sides that are located on the inner peripheral side and are in contact with a pulley of a continuously variable transmission when they are stacked in a ring shape and bound in a ring shape A head that is connected to the body via a pair of grooves for mounting a pair of endless rings that are positioned on the outer peripheral side when a plurality of annularly stacked layers, a convex portion formed on the front surface of the head, An element forming method for forming an element of a continuously variable transmission belt including a concave portion formed on the back surface of the convex portion from a plate material, while suppressing the flow of the plate material portion of the portion to be the head, It comprises a punching step of forming the recess and the protrusion and punching at least the outer periphery of the head of the element.

  According to the element forming method for a continuously variable transmission belt of the present invention, in the punching step, the concave portion and the convex portion are formed while suppressing the flow of the portion of the plate material that becomes the head. Therefore, a possibility that a shrinkage may occur in the concave portion or the convex portion of the element can be reduced.

In the element forming method for a continuously variable transmission belt according to the present invention, the pressing surface for pressing the plate material in the punching step protrudes toward the plate material side at a position spaced from the end of the head to suppress the flow. It is provided with a protrusion.

Thereby , it becomes possible to suppress the flow of the material with a simple configuration.

  When the protruding portion is separated from the end of the head by a distance less than 1/3 of the plate thickness of the plate material, the load on the punching die becomes too large, and the punching die may be damaged. On the other hand, if the protrusion exceeds the plate thickness of the plate and is separated from the end of the head, from the inventor's experiment, the flow of the material cannot be sufficiently suppressed, and the bottom of the recess is dragged. May occur.

  Therefore, in the element forming method for a continuously variable transmission belt according to the present invention, the protruding portion is provided at a position spaced from the end of the head at a distance equal to 1/3 to the plate thickness of the plate member. It is preferable.

  Further, if the protruding height of the protruding portion is less than 1/6 of the plate thickness, the inventor's experiment cannot sufficiently suppress the flow of the material, and the bottom of the concave portion may be dragged. Occurs. On the other hand, if the protruding height of the protruding portion exceeds the plate thickness, the load on the punching die becomes too large and the punching die may be damaged.

  Therefore, it is preferable that the protruding height of the protruding portion is 1/6 to 1/3 of the plate thickness of the plate material.

  In addition, when the projecting portion and the recessed portion have a circular cross-section and the projecting portion extends in the same direction in the groove extending direction with respect to the projecting portion and the projecting portion, the length of the projecting portion in this direction is the diameter of the projecting portion. If it is less than 1.5 times, from the inventors' experiments, the flow of the material cannot be sufficiently suppressed, and there is a possibility that the bottom on the rear end side of the recess may be closed. On the other hand, if the width of the protruding part exceeds 3.5 parts of the diameter of the convex part, from the inventor's experiment, the flow of the material is excessively suppressed, and there is a possibility that the bottom of the concave part on the tip side may shrink. Arise.

Therefore, in the element forming method for a continuously variable transmission belt according to the present invention, the protrusion is symmetric with respect to a center line that passes through the center of the protrusion and bisects the element symmetrically, and The width in the direction perpendicular to the center line is 1.5 to 3.5 times the diameter of the convex portion.

  In the element forming method for a continuously variable transmission belt according to the present invention, it is preferable that a tip end surface of the protruding portion is flat.

  In this case, compared with the case where the lower end surface of the protrusion is not flat, the punching die is not locally loaded.

An element forming device for a continuously variable transmission belt according to the present invention includes a body having V surfaces on both sides that are located on the inner peripheral side and are in contact with a pulley of a continuously variable transmission when they are stacked in a ring shape, A head that is connected to the body via a pair of grooves for mounting a pair of endless rings that are positioned on the outer peripheral side when a plurality of annularly stacked layers, a convex portion formed on the front surface of the head, An element forming device for forming an element of a continuously variable transmission belt from a plate material, comprising a concave portion formed on the back surface of the convex portion, and forming the concave portion and the convex portion, and at least an outer periphery of the element And a pad having a pressing surface for pressing the plate material, and the pressing surface faces the plate material side at a position spaced from the punched portion of the head of the punching die. And protrusions formed protruding Te, the convex portion and the concave portion is circular in cross section, the protrusion is symmetrical with respect to the center line bisecting the street the element the central portion of the convex portion symmetrically And the width in the direction perpendicular to the center line is 1.5 to 3.5 times the diameter of the convex portion.

  According to the element forming method for a continuously variable transmission belt according to the present invention, when forming the concave and convex portions and punching at least the outer periphery of the head, the flow of the plate material portion of the portion that becomes the head is caused. While being restrained by the protruding portion, the concave portion and the convex portion are formed. Therefore, a possibility that a shrinkage may occur in the concave portion or the convex portion of the element can be reduced.

It is a figure which shows the state in which the endless ring was mounted | worn with the element formed by the element formation method which concerns on embodiment of this invention, Comprising: FIG. 1A is a front view, FIG. 1B is the II sectional view taken on the line of FIG. Explanatory drawing which shows typically the punching process which punches an element with the element formation apparatus which concerns on embodiment of this invention. Explanatory drawing which shows typically lower surfaces, such as an element formation punch and a pad, in the element formation apparatus shown in FIG.

  Hereinafter, a method and an apparatus for forming an element of a continuously variable transmission belt according to an embodiment of the present invention will be described.

  The element forming method of this embodiment is used when manufacturing an element for a continuously variable transmission (hereinafter simply referred to as an element) 1 shown in FIGS. 1 (a) and 1 (b). The element 1 is a member that forms a belt for a continuously variable transmission by being stacked in a large number so as to form an annular shape as a whole and bound together by a metal endless ring A. Although the endless ring A is not shown in detail, the endless ring A is formed by stacking a plurality of ring members formed in a plate shape.

  The element 1 includes a substantially triangular head 2 positioned on the outer peripheral side when a continuously variable transmission belt is formed, and a body 3 positioned on the inner peripheral side. The head 2 and the body 3 are integrally connected via a neck 4. A pair of grooves (slits) 5 formed by the neck 4 between the head 2 and the body 3 are fitted with an endless ring A when the continuously variable transmission belt is formed. Further, a pair of V surfaces 6 are provided at both ends of the body 3 so as to contact the pulley B of the continuously variable transmission indicated by phantom lines in the drawing.

  A recess 7 is formed near the center of the front surface, which is one surface of the head 2. A convex portion (nose) 8 is formed in the vicinity of the central portion of the back surface, which is the other surface of the head 2, corresponding to the concave portion 7.

  The concave portion 7 has a circular cross section, and the convex portion 8 is formed of a cylindrical protrusion having a circular cross section that enters the concave portion 7 with a slight gap. The height of the convex portion 8 is slightly smaller than the depth of the concave portion 7. Moreover, the recessed part 7 and the convex part 8 incline so that the side peripheral surface may spread toward the back side from the front surface. When the continuously variable transmission belt is formed, the convex portions 8 of the elements 1 stacked adjacent to each other enter the concave portion 7, whereby the mutual positional relationship between the elements 1 is determined.

  The element 1 is formed symmetrically with respect to the center line CL, and the centers of the concave portion 7 and the convex portion 8 are also located on the central line CL.

  As shown in FIG. 2, the manufacturing process of the element 1 includes a punching process in which the element 1 is punched from the plate 11 while leaving the connecting portion 12 using the forming method according to the present embodiment, and the connecting portion 12 and the element 1. And a separation step of separating the element 1 from the plate 11 by punching and cutting along the boundary.

  The plate material 11 is made of alloy steel such as carbon tool steel or alloy tool steel, and has a plate thickness of, for example, about 1.5 mm to 3.0 mm.

  In addition, the manufacturing process of the element 1 may be provided with the preliminary | backup punching process which forms the board | plate material 11 in the shape substantially similar to the shape where the element 1 was connected via the connection part 12 before the punching process. Furthermore, before this preliminary punching step, a crushing step may be provided in order to reduce the thickness of the plate material 11 of the thin portion of the body 3.

  The punching process is performed by the element forming apparatus 20 according to the embodiment of the present invention. The forming apparatus 20 includes a die 21 on which the plate material 11 is placed, and an element forming punch 22 that punches the plate material 11 on the die 21 into an element shape leaving the connecting portion 12. A counter punch 23 that descends following the descending of the element forming punch 22 is provided at a position facing the element forming punch 22.

  Further, a concave portion forming punch 24 is provided on one side of the element forming punch 22 in order to form the concave portion 7 and the convex portion 8. A recess 25 is formed in the counter punch 23 corresponding to the recess forming punch 24.

  Further, a connecting portion forming punch 26 is provided on one side of the element forming punch 22 in order to form the connecting portion 12. An escape portion 27 is formed in a part of the die 21 corresponding to the connecting portion forming punch 26.

  A pad 28 for pressing the plate material 11 on the die 21 is provided above the die 21. The pad 28 holds the plate material by pressing the pressing surface 28a, which is the lower surface thereof, against the plate material 11.

  A protruding portion (notch) 29 that protrudes toward the plate material 11 is formed at a position of the pressing surface 28 a that is spaced from the tip of the head 2. As shown in FIG. 3, the protruding portion 29 has a V shape that is symmetrical with respect to the center line CL along the shape of the distal end portion of the head 2 and has a small curvature in a bottom view.

  In the forming apparatus 20, first, the plate material 11 placed on the die 21 is fixed on the die 21 by pressing the pad 28. Next, the element 1 is punched out while leaving the connecting portion 12 by the descending of the element forming punch 22 while being held from below the plate material 11 by the counter punch 23.

  At the same time, the concave portion 7 and the convex portion 8 of the element 1 are formed by the concave portion forming punch 24 lowered together with the element forming punch 22 and the concave portion 25 of the counter punch 23. At the same time, the connecting portion 12 is formed by the connecting portion forming punch 26 that is lowered together with the element forming punch 22 and the relief portion 27 on the die 21 side corresponding to the connecting portion forming punch 26.

  Subsequently, by raising the element forming punch 22, the recess forming punch 24, the connecting portion forming punch 26, the counter punch 23, and the pad 28, the plate material 11 in a state where the element 1 is connected via the connecting portion 12 is taken out. , Supplied to a forming apparatus (not shown).

  Thereafter, using this forming apparatus, a separation process is performed in which the element 1 is punched along the boundary with the connecting portion 12 to separate the element 1 from the plate material 11. In this way, element 1 is obtained.

  As described above, according to the element forming method using the forming apparatus 20 according to the embodiment of the present invention, in the punching step, the outer periphery of the element 1 including the head 2 and the like is punched, and at the same time, the concave portion 7 and the convex portion. When the 8 is formed by a shearing process, the flow of the material generated by the shearing process is suppressed by the protrusions 29. Thereby, it is possible to suppress the occurrence of sagging or the like in the concave portion 7 and the convex portion 8. If sagging or the like occurs in the concave portion 7 or the convex portion 8 and a desired shape cannot be obtained, the assembly accuracy of the continuously variable transmission belt formed using the element 1 deteriorates, and the transmission efficiency of the continuously variable transmission is reduced. May decrease.

  2 and 3, it is preferable that the distance L from the end of the head 2 is (1/3) t to t, where t is the thickness of the plate 11 and . If the distance L is less than (1/3) t, the load on the die 21 becomes excessively large and the die 21 may be damaged. However, the distance L may be less than (1/3) t as long as the strength of the die 21 can be sufficiently secured. On the other hand, if the distance L exceeds t, the inventor's experiment cannot sufficiently suppress the flow of the material, and the bottom of the recess 7 may be contracted.

  Moreover, it is preferable that the protrusion height H of the protrusion part 29 is (1/6) t- (1/3) t. If the protrusion height H is less than (1/6) t, the inventor's experiment cannot sufficiently suppress the flow of the material, and the bottom of the concave portion 7 may be contracted. On the other hand, when the protrusion height H exceeds t, the load on the die 21 becomes too large, and the die 21 may be damaged. However, if the strength of the die 21 can be sufficiently secured, the protruding height H may exceed (1/3) t.

  Further, the width W in the left-right direction of the protrusion 29 is preferably 1.5 to 3.5 times the diameter p of the protrusion 8. If the width W is less than 1.5p, the inventor's experiment cannot sufficiently suppress the flow of the material, and there is a possibility that the bottom of the rear end side of the recess 7 may be dragged. On the other hand, if the width W exceeds 3.5 p, the inventor's experiment results in excessive suppression of the material flow, and there is a possibility that the bottom of the recess 7 may be contracted.

  Moreover, it is preferable that the lower end surface of the protrusion part 29 is flat. This is because a load is not locally applied to the die 21 if the lower end surface of the protruding portion 29 is flat. However, as long as the strength of the die 21 can be sufficiently secured, the lower end surface of the protruding portion 29 may not be flat, and may be, for example, a shape protruding in a V shape.

  Furthermore, in the present embodiment, the shape of the protruding portion 29 is a V shape having a small curvature in the bottom view, but is not limited thereto. For example, the protrusion may extend linearly in the left-right direction when viewed from below.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, The structure and form of a formation apparatus can be changed suitably.

DESCRIPTION OF SYMBOLS 1 ... Element, 2 ... Head, 3 ... Body, 4 ... Neck, 5 ... Groove, 6 ... V surface, 7 ... Recessed part, 8 ... Convex part, 11 ... Plate material, 12 ... Connection part, 20 ... Element formation apparatus, 21 ... Die, 22 ... Element formation punch, 23 ... Counter punch, 24 ... Recess formation punch, 25 ... Recess, 26 ... Connection part formation punch, 27 ... Relief part, 28 ... Pad, 28a ... Presser surface, 29 ... Projection part, A: Metal endless ring, B: Pulley.

Claims (5)

The body is provided on both sides with a V surface that is located on the inner peripheral side and contacts the pulley of the continuously variable transmission when stacked in a ring shape, and a pair of grooves for mounting a pair of endless rings that are bundled in a ring shape. A steplessly provided with a head that is connected to the body and positioned on the outer peripheral side when a plurality of layers are annularly stacked, a convex portion formed on the front surface of the head, and a concave portion formed on the back surface of the convex portion An element forming method for forming an element of a transmission belt from a plate material,
A punching step of punching at least the outer periphery of the element and forming the concave portion and the convex portion while suppressing the flow of the plate material portion of the portion to be the head;
Protruding portions that protrude toward the plate material side and suppress the flow are provided at positions spaced from the end of the head of the pressing surface that holds the plate material in the punching step,
The convex portion and the concave portion are circular in cross section,
The protrusion is symmetrical with respect to a center line that bisects the element symmetrically through the center of the protrusion , and a width in a direction perpendicular to the center line is 1. A method for forming an element of a belt for a continuously variable transmission, wherein the element is 5 to 3.5 times. 2. The continuously variable transmission according to claim 1 , wherein the projecting portion is provided at a position spaced apart from an end portion of the head at a distance equal to 1/3 to a plate thickness of the plate member. For forming a belt element. The element forming method for a continuously variable transmission belt according to claim 2 , wherein the protruding height of the protruding portion is 1/6 to 1/3 of the plate thickness of the plate member. 4. The element forming method for a continuously variable transmission belt according to claim 2, wherein a tip end surface of the protruding portion is flat. The body is provided on both sides with a V surface that is located on the inner peripheral side and contacts the pulley of the continuously variable transmission when stacked in a ring shape, and a pair of grooves for mounting a pair of endless rings that are bundled in a ring shape. A steplessly provided with a head that is connected to the body and is positioned on the outer peripheral side when a plurality of layers are annularly stacked, a convex portion formed on the front surface of the head, and a concave portion formed on the back surface of the convex portion An element forming apparatus for forming an element of a transmission belt from a plate material,
A punching die for forming the concave portion and the convex portion and punching at least an outer periphery of the element; and a pad having a pressing surface for pressing the plate material;
In the pressing surface, a protruding portion that protrudes toward the plate material side is formed at a position separated from a portion of the punching die that punches the end of the head.
Protruding portions that protrude toward the plate material side and suppress the flow are provided at positions spaced from the end portion of the head of the holding surface that holds the plate material,
The convex portion and the concave portion are circular in cross section,
The protrusion is symmetrical with respect to a center line that bisects the element symmetrically through the center of the protrusion , and a width in a direction perpendicular to the center line is 1. A belt element forming device for a continuously variable transmission, characterized in that it is 5 to 3.5 times.